Slow boot up and overall very slow performance

I have openSUSE Leap 42.1 running on my HP Laptop i5 - 4th Gen, 8 GB RAM ]. At first, I was overwhelmed by the features and the look and feel of Plasma 5 DE. But now that joy has been overtaken by the frustration of slow boot up, slow loading up of apps (Firefox for example) and slow shut down.
Read somewhere in the forum that due to heavy indexing, initially after a fresh install the system may be slow and later it would be fine.
Since, I am a first time user of openSUSE (previously tried Linux Mint 17.3 Cinnamon), I do not know much about it.
Any suggestions for improving the performance of the overall system are requested. I only intend to use openSUSE for my development tasks, multimedia features are not that desired.

Hi!
Perhaps you can find something useful here:
https://doc.opensuse.org/documentation/html/openSUSE_122/opensuse-tuning/cha.tuning.io.html

And there is an old thread about it. The links doesn’t work, but if I find something similar to them, I will write!
https://forums.opensuse.org/showthread.php/480883-Improving-opensuse-performance-(boot-time-and-memory-consumption)

(I’m not an expert openSuse user, so personally I can’t really give any useful advice.)

I hope it helped!

And one more thing: please post the output of the

systemd-analize

command!